1. Field of the Invention
This invention relates to rotary head type recording apparatus, and more particularly to such apparatus which records informations or video signals on a tape-shaped recording medium along oblique lines by a rotating head.
2. Description of the Related Art
A typical example of the recording apparatus of this kind is the video tape recorder (VTR). Recently, the trend of VTRs toward the reduction of the size and the increase of the recording density has advanced until a magnetic tape of 8 mm. width is usable, or a so-called 8 mm. VTR is available in the market.
Such a light weight VTR has a high frequency of outdoor use. So, this leads to an earnest desire for an editing capability that allows so-called cuts or erasions and subsequent insertions to be performed. To this end, a rotary erasing head has come to be used, because the failure of leaving unerased the part which was intended to be erased is less than when a stationary erasing head is used.
Furthermore, to realize increased recording density, use has been made of magnetic tapes with a high coercive force referred to as metal tapes. In order to erase this type magnetic tape, the current to the rotary erasing head must be increased.
Aiming at a further increase in the recording density, another kind of VTR has been developed that enables two or more different pitches to be selectively set. In such a recorder, particularly when the recording is performed with the narrow pitch, the amount of consumed electrical power by the erasing current is caused to increase.
Another problem arising from the reduction of the size of the drum is the increased possibility of leakage of the erasing current to another head through a rotary transformer. This leakage reduces the quality of the reproduced picture when the picture is recorded in tracks of narrow pitch.